For many years lactic acid bacteria have been used for increasing the shelf life of food products. During fermentation the lactic acid bacteria produce lactic acids and other organic acids thereby reducing the pH of the food product making it unfavorable to the growth of unwanted microorganisms, such as pathogenic bacteria, yeasts and fungi.
Additionally, some lactic acid bacteria also produce metabolites with antimicrobial activity.
European Patent Application no. EP0221499 describes the antifungal properties of Lactobacillus rhamnosus NRRL-B-15972 which is capable of inhibiting the growth of different molds when cultured on agar medium supplemented with cucumber juice.
European Patent Application no. EP0576780 is related to Lactobacillus rhamnosus LC-705 which can inhibit the growth of Penicillium, Cladosporium, Fusarium and Candida on a lactoserum-based medium, supplemented with casein hydrolysate and with yeast extract.
European Patent Application no. EP1442113 is directed to mixtures of Propionibacterium jensenii and Lactobacillus sp., such as Lactobacillus rhamnosus, with antimicrobial activities for use for bioprotection.
However, there is still a need for bioprotective agents with an improved antifungal effect as single strains or in combination with other bioprotective strains.